Chrome-plated steel and aluminum bumpers have been available for heavy weight trucks for a number of years to enhance the appearance of the truck. However, as soon as a fastener is inserted through the chrome-plated steel or aluminum bumper and tightened to secure the bumper to the truck body, the brittle, thin chrome plating is fractured, and the corrosion process immediately starts. It is then simply a matter of time before the corrosion appears, thus ruining the visual appearance and effect of the shiny chrome. As the corrosion process continues, the chrome plating separates from the base metal, further distracting from the appearance of the bumper. Further corrosion also affects the structural integrity of the bumper. Eventually, the truck owner replaces the unsightly and structurally weakened bumper, and the corrosion process repeats itself as soon as the fasteners are tightened.
One attempt to solve the problem has been to weld threaded studs to the back surface of the bumper. These welded studs replace the use of fasteners that are inserted through the bumper to secure it to the truck body. These threaded studs are typically spot welded to the bumper, which provides minimal attachment force. Spot welds easily fracture when the bumper and, particularly a heavy weight truck bumper, is subjected to an impact or the constant vibration of the truck. A larger surface weld or fillet can be applied to the rear surface of the bumper and the threaded stud with the result that the structural integrity of the stud is weakened due to the heat. Furthermore, this larger weld also heats a larger area of the chrome-plated bumper and for a longer period of time. This can result in the chrome-plating being compromised in the heated area. Separation of the chrome plating from the base metal occurs, and the corrosion process is again enhanced.
Fasteners or apertures placed through any bumper visually distract from the uniform shiny appearance of the exterior bumper surface. The fasteners or aperture edges also reflect light at different angles than the bumper surface, thereby creating a safety concern for oncoming traffic.
A chrome-plated plastic layer has also been utilized, but even the most minor impact fractures the brittle chrome plating as well as the plastic layer.
Stainless steel has been utilized for truck bumpers, but any thickness sufficient for structural integrity is limited to a dull or not very bright surface. Furthermore, any fasteners placed through the stainless steel plate also distract from the visual appearance thereof
Stainless steel has also been utilized for other truck parts such as fenders, which have been chrome-plated. However, the stainless steel utilized in these chrome-plated parts is 430 series stainless steel, which is high in chromium and susceptible to oxidation. As a result, as soon as the chrome plating is fractured or compromised, the base stainless steel metal oxidizes with the corrosion appearing through the fracture or compromised area.